Yeah, the old adage applies that the people making money and the people writing books on how to make money are different people.
Which then boils down to the student caution to ascertain whether the advice a solid professor is giving you has changed, since they last successfully did.
And also the observation that the number of students who are likely to be more successful ignoring education is pretty small: most people aren't that brilliant and will get better mileage out of learning and...